By William Lee
From Chicago Tribune
Chicago–Family portrait takers, tour guides and social media influencers are running out of time to photograph the final days of the best season of fall colors in northern Illinois in years, experts say.
The Chicago area may have the best colors of the entire state, as other parts continue to struggle with dry conditions.
The color change is triggered by cooler seasonal temperatures that cause trees to stop producing chlorophyll, which makes leaves green and powers photosynthesis, in preparation for the cold winter months. As leaves lose their special pigment, their colors change from vibrant to a dull brown.
Honeylocust ginkgo, buckeyes and tulip tree leaves, for example, turn yellow, while sugar and Japanese maples, sweetgum, sumac and pin oaks turn orange or reddish as the weather cools.
Fall colors are at their peak when leaves bloom to bright colors such as reds and yellows just before they die and fall to the ground by the millions.
While the color change process is inevitable, it doesn’t run like clockwork. Various factors such as moisture and temperature can affect how brightly the colors can change.
“There’s a world of variability in fall color,” said David Griffith, district forester for the northeastern counties with the Illinois Department of Natural Resources. “It’s still up in the air, things are looking good right now, though. We’ve been getting some late summer rains … so far so good.”
Similarly, Tim Johnson, the Chicago Botanic Garden’s senior horticulture director, said he thinks this fall will be the best in recent years thanks to the weather pushing the leaf colors to peak about a week earlier than usual.
“I’m fortunate that I can get out and walk around the gardens here so I’m seeing it firsthand and I’m seeing some great colors already,” Johnson said.
According to the IDNR’s interactive fall color trip planner, northern Illinois’ leaves are peaking in mid-October, extending toward the final week of the month. Recent rain could help the progression of fall colors, but area weather will have to be just right.
“The weather’s setting up really well and we’ve had some rains recently,” Johnson said. “The best color is going to come when you have bright, sunny days and cool nights and we’re getting a good amount of that now.”
Recently, Illinois has had consecutive years of subpar fall colors tied to a 2012 drought that ravaged the Midwest and continues to wreak havoc on trees.
“If we have a super dry spring, that might lead to lackluster fall color,” said Griffith, a 16-year veteran with the IDNR. “If we have a very dry summer, that could actually stress the trees and send them into dormancy early. “Now we’re at the point where really as long as we can have warm days and cool nights — not freezing — we’re at this stage now that’s going to determine the fall color the most.”
While many may associate the changing leaves with Halloween, Griffith and Johnson agree that leaves will likely be past the peak by the end of the month, so now is the best time to travel through forest preserves, wooded areas and the Botanic Garden in Glencoe.
The good news is that for those who miss the colors in northern Illinois, there is still a chance to take in the foliage at downstate parks and wooded areas. The bad news, Griffith said, is that the southern part of the state may not be as bold as Chicago.
“The fall color down in southern Illinois will not be nearly as good as the color in northern Illinois,” Griffith said.
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